Dual action laminar air flow

ABSTRACT

A multiple compartment air exhaust system comprising first and second compartments, the first compartment having a first air inlet located in its upper portion and a first exhaust opening located in its lower portion, the second compartment having a second air inlet located in its lower portion and a second exhaust opening located in its upper portion. The first exhaust opening is connected to the second air inlet by means of a conduit and means is provided for providing a positive air flow through the first air inlet, first compartment and first exhaust opening through the conduit, the second air inlet, the second compartment and the second exhaust opening.

[ July 29, 1975 DUAL ACTION LAMINAR AIR FLOW [75] lnventor: George J. Lada, Newport Beach,

Calif.

[73] Assignee: Allied Chemical Corporation, New

York, NY.

22 Filed: Jan. 25, 1974 21 Appl. No.: 436,577

OTHER PUBLICATIONS Austin Air Engineering, February 1968, pp. l8, l9 14, Types of Clean Rooms.

Primary ExaminerBernard Nozick Attorney, Agent, or Firm.lay P. Friedenson; Michael L. Dunn [57] ABSTRACT A multiple compartment air exhaust system comprising first and second compartments, the first compartment having a first air inlet located in its upper portion and a first exhaust opening located in its lower portion, the second compartment having a second air inlet located in its lower portion and a second exhaust opening located in its upper portion. The first exhaust opening is connected to the second air inlet by means of a conduit and means is provided for providing a positive air flow through the first air inlet, first compartment and first exhaust opening through the conduit, the second air inlet, the second compartment and the second exhaust opening.

5 Claims, 5 Drawing Figures PATENTED JUL 2 9 I975 SHEET WWII I iI-"-+ J:

PATENTED JULZ 9 I975 PATENTED JUL 2 9 I975 SHEET DUAL ACTION LAMINAR AIR FLOW BACKGROUND OF THE INVENTION This invention relates to a laminar air flow exhaust system for containing and exhausting odoriferous, toxic or otherwise undesirable vapors or fumes from a process area. In the prior art when multiple operations were used for processing an article in which some of the operations employed substances emitting odoriferous, toxic or otherwise undesirable vapors or fumes, air was sucked or blown into the processing area and was then exhausted to the exterior of the processing area. When some of the steps for processing an article employed materials which could contaminate or adversely affect other steps in processing the article, completely separate exhaust systems were used to avoid such contamination. Such separate exhaust systems required multiple sets of apparatus such as fans, exhaust ducts and filters. In addition air flow from an inlet located in the upper portion of a processing station to an exhaust in the lower portion of the processing station required exhaust ducts running from the lower portion of the station to a higher position for final exhausting from the apparatus since exhausting of undesirable vapors or fumes at or near ground level pollutes the atmosphere at or near ground level thus creating unacceptable conditions for persons located near the position where the vapors or fumes leave the exhaust ducts.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front elevational view of a dual compartment air exhaust system in accordance with this invention showing the flow of air from a first compartment to a second compartment in conjunction with an apparatus for processing and conveying articles.

FIG. 2 is an end view showing the flow of air through the second compartment.

FIG. 3 is an end view showing the flow of air through the first compartment.

FIG. 4 is a top cross sectional view of the dual compartment air exhaust system taken on line 4-4 of FIG. 1; and

FIG. 5 is a cut away cross sectional front view taken on line 5-5 of FIG. 4 showing the air flow from the first compartment to the second compartment.

BRIEF DESCRIPTION OF THE INVENTION In accordance with this invention a multiple compartment air exhaust system is provided comprising first and second compartments which permits a single stream of air to be utilized for exhausting both first and second compartments in which clean air for exhausting the first compartment must be used. The air used in the first compartment cannot be contaminated by vapors or fumes from materials used in the second compartment. The dual compartment air exhaust system in accordance with this invention permits the use of only one set of exhaust ducts and permits a flow of clean air from the upper portion to the lower portion of the first compartment without requiring separate and special ducts running from the lower portion of the first compartment to an elevated exhaust station.

In accordance with this invention a multiple compartment air exhaust system is provided which comprises first and second compartments which are separatedv The compartments may be separated by any means which will assist in preventing a flow of air through the second compartment, which may contain air contaminated by vapors or fumes, from mingling or mixing with air flowing through the first compartment. Examples of suitable separating means are solid impermeable walls or baffles which separate air flow in the first compartment from air flow in the second compartment.

The multiple compartment air exhaust system further comprises a first air inlet located in the upper portion of the first compartment, a first exhaust opening located in the lower portion of the first compartment. a second air inlet located in the lower portion of the second compartment, a conduit connecting the first exhaust opening and the second air inlet, and a second exhaust opening located in the upper portion of the second compartment.

In addition the multiple compartment air exhaust system comprises means for providing a positive flow of air through the first air inlet downwardly through the first compartment into the first exhaust opening. through the conduit to the second air inlet, upwardly through the second compartment and through the second exhaust opening. The first exhaust opening, the conduit and the air inlet may together comprise an opening in the lower portion of any wall or baffle separating the compartments.

PREFERRED EMBODIMENT OF THE INVENTION In accordance with the preferred embodiment of this invention only the required first and second compartments are provided although in accordance with the invention additional compartments could be used.

The first air inlet in the first compartment is preferably located proximate the uppermost portion of the first compartment and may be provided with vertically directed surfaces-for directing the flow of air in a downward direction. The air entering the first compartment through the firstair inlet preferably first passes through an air filter to remove contaminating particles.

The first exhaust opening is preferably located in the lowermost portion of the first compartment. The first exhaust opening is most preferably a grill located along the lowermost portion of the front of the compartment.

The second air inlet is preferably located in the lowermost portion ofthe second compartment and in the preferred embodiment is a grill along the front of the second compartment which directs air entering the compartment in an upward direction. The second air inlet is connected to an air conduit which may be any suitable enclosed space such as a metal duct or a hollow pipe and the second exhaust opening is preferably located in the uppermost portion of the second compartment so that the flow of air through the second compartment will enter the second air inlet and flow upwardly to the second exhaust opening.

The means for providing a positive air flow may be any suitable means for forcing or directing air downwardly through the first compartment and upwardly through the second compartment and may include one or more air blowers for providing positive air pressure at the inlets, one or more air exhaust devices for providing negative air pressure at the exhaust opening and baffles or walls for directing the flow of air from the first inlet to the first exhaust opening and from the second inlet to the second exhaust opening. In the preferred embodiment the means for providing positive air flow comprises an air blower for blowing air through the first inlet into the first compartment and may additionally comprise an air exhaust device for pulling air from the second compartment through the second exhaust opening.

The means for providing a positive air flow may also include one or more air directing devices such as baffles or air directing surfaces such as the surfaces of one or more grills which may be located at the air inlets or at the exhaust openings.

The flow of air through the first and second compartments is preferably laminar air flow, i.e. a regular, continuous non-turbulent movement of air from the first inlet to the first exhaust opening and from the second inlet to the second exhaust opening. The flow of air is preferably along the front portion of each of the compartments and is essentially unaffected by surrounding static air, that is the front of each compartment can be opened to the atmosphere and air from the flow will not enter the surrounding atmosphere. In addition the flow of air along the front portion of each of the compartments is desirably in the form of a sheet of air created by running the first exhaust opening and the second inlet along substantially the entire length of the lowermost portion of the front of each of the compartments.

Referring to the drawings, FIG. 1 shows a preferred embodiment of the invention wherein an airflow 10 is filtered through filter 14 and enters first compartment 12 through first inlet 11. Airflow 10 is forced through air filter 14 under positive pressure by means of the motor and fan 16. As best seen in FIGS. 4 and 5 airflow continues through first compartment 12 to an exhaust opening in the form of a grill 18 located in the lower portion of first compartment 12. Airflow 10 is conducted from the exhaust opening to a second inlet in the form of grill 20 located in the lower portion of second compartment 22 by means of a conduit in the form of enclosed space 24. Airflow 10, as best seen in FIGS. 1 and 2, passes through grill 20 into second compartment 22 and through second compartment 22 to second exhaust opening 26 located in the upper portion of second compartment 22.

As best seen in FIGS. 2, 3 and 4, grills 18 and 20 are located in the front portion of working surface 28 located in the bottom of compartments 12 and 22. The compartments may be completely closed or may have openable front portions 30 and 32 as seen in FIGS. 2 and 3 respectively. First compartment 12 and second compartment 22 may be completely separated or partially separated by a baffle 34 which permits passage of an article or workpiece 36 over, around or through the baffle by means of conveying mechanism 38.

The second compartment may be provided with an exhaust means in the form of an electrically driven rotary fan 40 located proximate second exhaust opening 26 to assist in movement of airstream 10 through the exhaust opening.

I claim:

1. A multiple compartment air exhaust system comprising:

first and second separated compartments;

a first air inlet located in the upper portion of the first compartment;

a first exhaust opening located in the lower portion of the first compartment;

a second air inlet located in the lower portion of the second compartment;

a conduit connecting the first exhaust opening and the second air inlet;

a second exhaust opening located in the upper portion of the second compartment; and

means connected to said first compartment for providing a positive flow of air through the first air inlet downwardly through the first compartment into the first exhaust opening, through the conduit to the second air inlet, through the second air inlet upwardly through the second compartment and through the second exhaust opening, each of said compartments being provided with an openable front portion and a working surface in its lower portion, the first exhaust opening and the second air inlet each being a grill located in the working surface along the length of and proximate to the front portion.

2. The dual compartment exhaust system claimed in claim 1 wherein the first and second compartment are separated by a baffle which permits passage of an article from the first to the second compartment by means of a conveying mechanism.

3. The air exhaust system of claim 2 wherein the means for providing a positive flow of air comprises an air blower for blowing air through the first inlet into the first compartment.

4. The air exhaust system of claim 3 wherein the means for providing a positive flow of air further comprises an air exhaust device to assist in pulling air from the second compartment through the second exhaust opening.

5. The air exhaust system of claim 4 wherein the air provided by the air blower passes through a filter before entering the first compartment. 

1. A MULTIPLE COMPARTMENT AIR EXHAUST SYSTEM COMPRISING: FIRST AND SECOND SEPARATED COMPARTMENTS, A FIRST AIR INLET LOCATED IN THE UPPER PORTION OF THE FIRST COMPARTMENTS, A FIRST EXHAUST OPENING LOCATED IN THE LOWER PORTION OF THE FIRST COMPARTMENT, A SECOND AIR INLET LOCATED IN THE LOWER PORTION OF THE SECOND COMPARTMENT, A CONDUIT CONNECTING THE FIRST EXHAUST OPENING AND THE SECOND AIR INLET, A SECOND EXHAUST OPENING LOCATED IN THE UPPER PORTION OF THE SECOND COMPARTMENT, AND MEANS CONNECTED TO SAID FIRST COMPARTMENT FOR PROVIDING A POSITIVE FLOW OF AIR THROUGH THE FIRST AIR INLET DOWNWARDLY THROUGH THE FIRST COMPARTMENT INTO THE FIRST EXHAUST OPENING, THROUGH THE CONDUIT TO THE SECOND AIR INLET, THROUGH THE SECOND AIR INLET UPWARDLY THROUGH THE SECOND COMPARTMENT AND THROUGH THE SECOND EXHAUST OPENING, EACH OF SAID COMPARTMENTS BEING PROVIDED WITH AN OPENABLE FRONT PORTION AND A WORKING SURFACE IN ITS LOWER PORTION, THE FIRST EXHAUST OPENING AND THE SECOND AIR INLET EACH BEING A GRILL LOCATED IN THE WORKING SURFACE ALONG THE LENGTH OF AND PROXIMATE TO THE FRONT PORTION.
 2. The dual compartment exhaust system claimed in claim 1 wherein the first and second compartment are separated by a baffle which permits passage of an article from the first to the second compartment by means of a conveying mechanism.
 3. The air exhaust system of claim 2 wherein the means for providing a positive flow of air comprises an air blower for blowing air through the first inlet into the first compartment.
 4. The air exhaust system of claim 3 wherein the means for providing a positive flow of air further comprises an air exhaust device to assist in pulling air from the second compartment through the second exhaust opening.
 5. The air exhaust system of claim 4 wherein the air provided by the air blower passes through a filter before entering the first compartment. 